The Scottish middle distance star left herself with considerable work to do before hitting the accelerator at the pivotal moment to burst clear of the field and retain the title she won in Berlin four years ago.
Muir, 29, clocked a red-hot time of 4:01.08 to finish 1.48s clear of Ireland’s Ciara Mageean - who ran a bold race to seal silver – and Poland's Sofia Ennaoui in front of a bumper crowd at the city’s 1972 Olympic Stadium.
The Inverness ace bagged a brilliant bronze at last month’s World Championships in Eugene before following it up with a long-awaited Commonwealth title in Birmingham.
Cramming three major championships into the space of five weeks was never going to be easy and Muir, who also won Commonwealth 800m bronze, admits it almost got the better of her after a gruelling sporting summer.
She said: “It looked hard on paper but actually doing it in person, never again.
“It was an amazing opportunity and a very unique one that we’d ever get three championships in a year, let alone in five weeks in the summer.
“It’s just insane but I said you know what, I’ll give it a go.
“I got a medal at all three and to win the Commonwealths and win here, I’m so happy.
“This was the hardest one – on paper it looked the easiest one event, only two rounds, but it’s the easiest out of the three physically.
“But it was so tough mentally – the most difficult race I think I’ve ever run.
“It was so hard – credit to all the other athletes who have done the three events, because it’s so difficult.”
Muir appeared to start sluggishly under the Friday night lights before kicking into gear ahead of the final lap to leave the rest of the field in the rear view mirror.
Mageean bravely attempted to live with Muir’s punishing pace but did not have enough in the locker as the Scot, who also won silver at last year’s Olympic Games in Tokyo, crossed the line in splendid isolation to prompt emotional scenes.
Muir added: “My coach looked at all the split and said nobody could match you over 400m, so if you give a good kick and maintain it, then I think you’ve got a good chance.
“Credit goes to him for the tactics – he made a good call there and I had to stick to it as best I could.
“Sometimes the 1500m is unpredictable and you never know, but it went to plan.”
Away from the Olympic Stadium, Eilish McColgan’s emotional sporting summer is now fuelling Deborah Kerr's quest for more British medals.Canoe sprint star Kerr, 24, enjoyed a brilliant morning on the Bavarian water after sailing into the finals in both of her events.
The Motherwell speedster joined forces with Emma Russell, Emily Lewis, and Rebeka Simon in the kayak four 500m before combining with Russell in the double to similarly advance to the weekend's medal showdown.
Canoe sprint is one of nine sports hosting their European Championships in Germany this week and Kerr has loved watching compatriot McColgan, who dramatically soared to athletics 10,000m and 5000m gold and silver at the Commonwealth Games, emulate her exploits at Munich's Olympic Stadium.The Dundee star won 10,000m silver and 5000m bronze this week and Kerr is now determined to follow in her decorated podium footsteps.She said: "I've really enjoyed watching Eilish McColgan this year."I've probably cried more than I imagined at some of her races."It makes you really proud to be a part of a team like this, that are doing so well."I'm only seeing it online but you can see the support all the British teams across the sports have for one another."It's nice to go online and on social media and see that another British athlete has qualified for the final - it makes you know you're part of that cohort."It's like we're a big family - and you can really feed off that."The multi-sport European Championships Munich 2022, featuring Athletics, Beach Volleyball, Canoe Sprint, Cycling, Gymnastics, Table Tennis, Triathlon, Rowing, Sport Climbing, takes place 11th-21st August on the 50th anniversary of the Olympics Games in the German city. Watch daily live coverage across BBC One, Two, Red Button, BBC iPlayer, BBC Sport website